Which ones are a Stronger Acid and Base?
CH3 is an electron-donating group relative to H, so it tends to place extra electron density around the nitrogen atom of CH3NH2. This makes the nitrogen atom more negative, so it can attract a proton better. Thus, CH3NH2 is stronger than NH3. NCl3, a very explosive oil, is a stronger base than NF3, because fluorine atoms are more electronegative than chlorine atoms (hence more electron-withdrawing), which means that the N in NF3 is more positive than it is in NCl3. Thus, the N in NF3 is less able to accept a proton (which is also positive). ClO- and ClO2- are conjugate bases of the acids HClO and HClO2, respectively. Since HClO2 is stronger than HClO, ClO2- must be weaker than ClO-, so ClO- is the stronger base. (Realize that oxygen atoms, since they are electron-withdrawing, lower basicity.) H2SeO4 is a stronger acid than H2SeO3. This is because extra oxygen atoms draw away electron density due to their electronegativity, making surrounding atoms more positive, which makes it easier f